"I suspect that whatever cannot be said clearly is probably not being thought clearly either" --- Peter Singer. (Mea culpa.) See the entry in my Quotes blog.

Friday, November 30, 2012

Receiver Interference Tolerance: The Tent Analogy

A postcript to my testimony (see previous post) at the House sub-committee on Communications and Technology hearing on receivers: It sounded like Rep. Walden, who chairs the sub-committee, hoped my oral presentation would've mentioned the tent analogy I included in the written testimony. So since at least one person liked it, here it is:
Imagine the property line between a two adjacent lots. (In the radio case, it would be a boundary between two frequency bands, not two geographic areas.)

Everyone has to take some responsibility for tolerating sounds that come from their neighbors. If I live in a tent, I’m going to be very sensitive to noise from next door. One response, and a typical one in spectrum policy, is to make the neighbors keep their voices down, i.e. limit the allowed transmit power in the adjacent band or perhaps even prohibit transmission altogether.

However, it seems unreasonable for me to demand that my neighbors always whisper when they’re in their own garden. I could also take some responsibility myself, for example by moving indoors; in radio terms, that’s analogous to adding receiver filters to exclude signals in the adjacent band.

I could ask the person I’m talking with to speak more loudly or come into the same room so that I can hear them better, or I could go to a room on the other side of the house. The radio analogy here would be to increase the desired radio signal level by increasing transmitter power or deploying more transmitters, or to move an operating channel away from the band boundary, respectively.